When a contact I made in Williston, North Dakota called me Monday night telling me there'd been another male rape, I wasn't sure what to think.

I'd heard the same story, from a different source, when I visited the town earlier this month to investigate the North Dakota oil boom. While the story didn't really have the ring of truth, I figured it was worth chasing down.

There's a reason people refer to the Northern Plains oil towns like Williston as something like the Wild West.

A ton of men are flocking to small towns for work, where there's a shortage of law enforcement, and very few women.

While I was in Williston, I met women who arrived with their husbands, women who were born in town, and women who came to work. There weren't many of them, and the ones I spoke with were all very aware of their small numbers.

Arnold was a school teacher born in Sidney, Montana — a small town that sits atop the Bakken oil field just like Williston. The two towns are about 45 miles apart, which is spitting distance in that part of the country.

Arnold was jogging one morning in January near her childhood home when she was kidnapped and killed by two workers fresh from Colorado looking to make their fortunes in the oil boom.

When arrested outside Lonnie's truck stop in Williston, the workers said they were so drunk they couldn't remember where they had buried Arnold after snatching her. They still haven't found her.

I first heard about Arnold from Crystal Keaster, 28, who came to Williston in September from Alaska, and the oilfields of Prudhoe Bay, to open a small coffee stand called C Cups Espresso in Williston.

"This is like the pipeline days in Alaska," Keaster told me as we huddled in her small stand and she brewed cups of coffee for drivers that pulled up to her window.

"It's like 80 to one, women to men, and I'll admit to having my concealed weapons permit." She finished making a cafe mocha for a bearded roughneck in an F-150 and turned back to face me. "As a woman, you can't be too careful." She shrugged. "It's just a matter of time before something happens."

Keaster, like the women I met at a church potluck, said they no longer go to Walmart alone--and rarely leave home without boyfriends or husbands.

There's just enough concern that rumors, like the male rapes, have taken a life of their own. A call to the Williston Police found that they agreed.

The police said the rape rumors, both male and female, keep popping up with no explanation. They say there's nothing to back it up, and have had no reports of sexual assaults in the past six months. Which is pretty good for a town that's grown from 12,000 to 30,000, and possibly better than most.

Another lingering rumor is that women are being followed to their cars in the Walmart parking lot. There's no proof of that either, but Erin Ling, a waitress at Lonnie's truck stop explained her reason for that to me while I was there.